[The SAPHO syndrome or psoriatic arthritis: a complicated differential diagnosis. Apropos 3 cases].

SAPHO syndrome is characterized by osteoarticular involvement of ventral chest wall in the form of sternocostoclavicular osteoarthritis and hyperostosis and skin changes such as palmoplantar pustulosis and acne. Occasionally, psoriatic lesions and sacroiliitis are observed. However, despite the higher frequency of psoriasis in this syndrome, its inclusion in psoriatic arthropathy spectrum is not clearly established. The authors report three cases of SAPHO syndrome in psoriatic patients commenting on the difficulty in differentiating this entity from psoriatic arthritis as well as its relationship with seronegative spondyloarthropathies. This disease has been described mainly in Japan and only a few cases of this disease have been reported in the European or American literature.